Non-contact thermal sensing on acoustic-enabled IoT devices

Temperature is an important source of information for personal health, weather forecasting, and thermal management in buildings and computing infrastructure, etc. Temperature measurement can be achieved via low-cost hardware with reasonable accuracy. However, large-scale distributed thermal sensing is non-trivial and currently relies on dedicated hardware. In this paper, we design the first software sonic thermometer (SST) using commercial-off-the-shelf acoustic-enabled devices. We utilize on-board dual microphones on commodity mobile devices to estimate sound speed, which has a known relationship with temperature. SST is portable, contactless, and cost-effective, making it suitable for ubiquitous sensing. We implement SST on an Android smartphone and an acoustic sensing platform. Evaluation results show that SST can achieve a median accuracy of 0.54dGC even at varying humidity levels.